o2 durango does not engage into 4x4
To set the transfer case in 4x4 lo your Durango has to be in stand still, and in neutral. If it does not shift it can be the shift motor if the 4x4 has not been used for some time the motor can be stuck adn maybe you could take it out and grease it up or you have to change it out for a new one.
Search Dodge Durango Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Dodge Durango Experts